1. Field of the Invention
This invention relates to apparatus and method for removing coil wire from a stator.
2. Description of the Prior Art
Large electric motors have, as a part of their construction, stators having generally planar and parallel end faces intersected by a bore extending axially therethrough. A plurality of elongated longitudinal slots, defined by stator teeth, and radially extending and intersecting with both the bore and opposing end faces, hold a plurality of coil wires, as is well known in the motor construction art. The coil wires extend through the slot and run lengthwise with the slot and emerge from opposing ends of the slot at the end faces of the stator where they are turned so as to enter other slots of the stator. Such turnings are known as end turns. Often, each slot of the stator is provided with insulation and the coil wires themselves may be coated with varnish, or the like, for insulating properties.
Because of the value of the stator housing and the value of the wire coil, generally copper, it is highly desirable to separate the wire from the stator where the stator has become defective due to manufacturing or usage defects. In this manner, the stator housing may be reused for new windings and the removed wire may be sold as scrap.
One prior method of removing the wire was to sever the end turns from one end of the stator and, utilizing tongs connected to the other end turns, pull the wire from the stator. Such operation resulted in both teeth breakage and incomplete clearance of the wire from the slots.
Another method, suggested by F. Dombrowski, U.S. Pat. No. 4,030,184, included severing wire from one end of the stator, seating the stator in a fixed position, gripping the end turns from the opposing end of the stator, and then driving the seating means and stator away from the gripped wire to strip the wire from the stator.
Because prior methods have both damaged the stator housing and resulted in inefficient removal of the wire, much salvage has been done by hand, hammering the wire out with a punch. Misalignment of the punch could result in the scarring of the stator slots or breakage of the teeth.